Barrier system for aircraft of different sizes

ABSTRACT

An aircraft arrester system of the type in which a hook mounted on an aircraft engages with a wire connected to braking means, said wire being complemented by additional wires, each of the latter wires having a brake or brakes and each of said wires being arranged parallel and sequentially in the direction of aircraft movement to arrest the movement of aircraft of different weights, such aircraft being provided with additional arrester hooks each of which is intended to engage its respective wire to a number dependent upon the weight of an aircraft.

- o ilnited States Patent 1 in] 3,712,565

Walander 1 Jan. 23, 1973 5 RRIER SYSTEM FOR AIRCRAFT F l,306,860 6/1919Smith ..244 /l 10 E 1,627,614 /1927 MCNUH) U244 E [76] Inventor: KarlOve Torgny Walander, Elsa Primary Examiner-Trygve M. Blix Brandstromgata 5, Linkoping, Assistant Examiner-Paul E. Sauberer SwedenAttorneyMunson & Fiddler [22] Filed: Jan. 18, 1971 [57] ABSTRACT [21]Appl. No.: 107,345

An aircraft arrester system of the type in which a hook 0 mounted on anaircraft engages with a wire connected Foreign Application Prlorltl Datato braking means, said wire being complemented by Jan 23 1970 Sweden I lI 808701970 additional wires, each of the latter wires having a brake orbrakes and each of said wires being arranged I parallel and sequentiallyin the direction of aircraft movement to arrest the movement of aircraftof 58 d Mile-{10R ferent Weights, such aircraft being provided withaddi- 0 care '7 d tional arrester hooks each of which is intended to enlgage its respective wire to a number dependent upon [56] R f C a theweight of an aircraft.

e erences l e UNITED sfATEs PATENTS 3 Claims, 6 Drawing Figures3,502,289 3/1970 Kelly et al 244/1 10 A INVENTOR.

KARL OVE TORGNY WALANDER BY MUNSON & FIDDLER PATENTEDJMI 23 ms 3.712.565

SHEET 2 [IF 2 KARL OVE TORGNY WALANDER INVENTOR.

MUNSON & FIDDLER ATTORNEYS BARRIER SYSTEM FOR AIRCRAFT OF DIFFERENTSIZES BACKGROUND or THE INVENTION A large number of aircraft barrier andarresting systems are known to this art. One of the most popularaircraft arresting systems hitherto used employs a collapsible arresterhook that is mounted in the tail por' tion of the aircraft and isarranged to co-act with a stationarily-arranged aircraft arrestingapparatus, the main component of which consists of an arrester wireextending across the landing path of the aircraft and connected ateither end to one or more brake mechanisms.

Such systems have shown some efficiency up to arresting speeds of 70lmeters per second, depending on the particular construction of thesystem. A problem in this connection is one of providing systems forarresting the movement of different aircraft having widely differingtotal weights. One of the reasons why the provision of such a system isproblematical is because systems which are designed to produce brakingforces sufficient to stop the largest aircraft at high speeds produceloads which are too high for small aircraft. The problem most difficultto solve, together with other problems, are those connected with theloads represented by the arrester wire and the brakes, since these loadsat the initial period of the arresting operation must be accelerated tospeeds approximately equal to the speed of the aircraft being arrested.

These problems are solved by means of the present invention and in amanner which can-be readily performed in practice. There is provided inaccordance with the inventionfa system by which aircraft, which varywidely in total weight, can be arrested safely. Thus, the system of thepresent invention will fulfill the requirements of civilian airports,where aircraft varying between 50 to 300 tons total weight areaccommodated each day.

DESCRIPTION OF THE INVENTION The invention is illustrated in theaccompanying drawings in which:

FIG. 1 shows in side view an aircraft provided with three arrestinghooks; w

FIG. 2 illustrates in top plan view a landing path with three arrestingwires extending transversely across its longitudinal extension;

FIG. 3 illustrates in top plan view, the arrester wires in an extended,operative position, and

FIGS. 4, 5 and 6 illustrate modified embodiments of the invention.

In accordance with the invention, the aircraft are divided into a mannerof different classes, for example three, depending upon the maximumbraking force desired, this force substantially being co-related withthe maximum weight of the aircraft. Aircraft belonging in the lightestclass may be provided in a known manner with one arrester hook; aircraftin the next weight class with two arrester hooks etc.

FIG. 1 illustrates an aircraft provided with three arrester hooksindicated at 2, 3 and 4 and arranged in a line, one behind the other atthe tail portion of the aircraft. The stationary groundsystem'installedon the aircraft runway is illustratedin FIG. 2 and is-provided withthree transversely extending wires 5, 6 and 7 which are arrangedparallel to each other and each of which is I connected to itsrespective brake mechanism indicated at 8, 9 and 10.

The system operates substantially as follows:

If an aircraft belonging to the lighter class of aircraft and havingonly one single arrester hook, and this is in the dropped position,passes over the arresting system, the hook will engage with the firstwire and extend it, thereby braking the aircraft. If for one reason oranother the book should miss the first wire, because of hook bounce forexample, the following wires will act in reserve, as with existingsystems, although with the exception that in many cases the differentwires are connected to the same brake mechanism (brake pairs) which inthis case are intended to operate alternatively against one of severalpossible arrester wires.

In the case of a heavy aircraft for example, one with three hooks indropped position, the first hook will engage the first wire. As a resultof the mass force created, the hook will immediately swing up toapproximately a horizontal position, and consequently it is important toensure that the arrangement be so constructed that neither the hook northe first wire be able to actuate the remaining hooks for example, bystriking them, so as to cause these hooks to bounce. Under theseconditions, the next hook will engage the next wire, and so on, untileach hook has engaged its respective wire.

With a maximum number of hooks and corresponding arresting devices onthe ground, a braking force is obtained, if one hook misses, whichcorresponds to an aircraft in the next lowest weight class. Thus, theground system should include one more wire than the total number ofhooks, in order to provide for a reserve wire in the case of a missedwire.

FIG. 3 illustrates an aircraft provided with three hooks being arrestedby a ground system which includes three wires. It is of interest to notethe pattern of orientation of the wires as they are extended, whichplaces certain requirements on the positioning of the hooks on theaircraft.

In the embodiment of FIG. 4 the hooks are mounted so that eachsubsequent hook has a lower pivot center 11 than the preceding hook.This center need not be fixed, but may be movable relatively to theaircraft and accompany the hook as a part thereof.

In the embodiment of FIG. 5, the preceding hooks are prevented fromreaching the ground until the hook immediately behind has engaged itswire.

FIG. 6 illustrates the arrest 'of an aircraft provided with the hooksillustrated in FIG. 5.

In addition to its main function of enabling aircraft which vary greatlyin total weight to be arrested effectively, the arrangement of theinvention also provides a number of other advantages. For example, thecaptain of largeraircraft may select the maximum of arresting force instages, by dropping a reduced number of hooks, that is, if the arrestingoperation is not carried out at maximum aircraft speed. 4

Moreover, the ground devices can be so spaced from each other that theload peaks, which occur when wires and brakes are rapidly accelerated tohigh speeds, do not coincide in time, and thereby relieve the load onthe aircraft structure, particularly when only one large system isengaged.

The invention has been described in principle and without describing indetail the particular construction of the different components and themanner in which they are connected together. Such variations, however,are considered to be within the spirit of the invention.

Net structures composed of wire rope, cables, bands, hoses, strings orthe like can also be used without departing from the spirit of theinvention. Also, any form of brake mechanism can be used. The brakes maybe placed in different ways on one or both sides of the runway with thewires on their extensions placed over direction-changing pulleys.

What is claimed is:

1. A system for arresting aircraft upon touchdown on a landing runwaycomprising:

a. a plurality of cables suspended in spaced relationship across therunway and each being provided with torque absorption means adapted tobe actuated upon engagement with the aircraft;

b. the combination therewith of an aircraft having a plurality ofarreste'r hooks pivoted to the aircraft tail section and adapted to beselectively lowered into position for engagement with one of-saidcables;

c. said cables and said hooks being spaced from one another so as toprevent accidental contact between the hooks and successive cables asthe first hook is swung upward by the force of engagement with the firstone of the arresting cables, and so as to cause the other hooks tosuccessively engage a single one of the subsequent cables.

2. A system according to claim 1 comprising a greater number ofarresting cables than arresting hooks.

3. A system according to claim 1 in which the arresting hooks havesuccessively lower pivot points.

1. A system for arresting aircraft upon touchdown on a landing runwaycomprising: a. a plurality of cables suspended in spaced relationshipacross the runway and each being provided with torque absorption meansadapted to be actuated upon engagement with the aircraft; b. thecombination therewith of an aircraft having a plurality of arresterhooks pivoted to the aircraft tail section and adapted to be selectivelylowered into position for engagement with one of said cables; c. saidcables and said hooks being spaced from one another so as to preventaccidental contact between the hooks and successive cables as the firsthook is swung upward by the force of engagement with the first one ofthe arresting cables, and so as to cause the other hooks to successivelyengage a single one of the subsequent cables.
 2. A system according toclaim 1 comprising a greater number of arresting cables than arrestinghooks.
 3. A system according to claim 1 in which the arresting hookshave successively lower pivot points.